Boys account for 5 / 9 of the total number in class 52. After 4 girls are transferred, boys now account for 3 / 5 of the total number

Boys account for 5 / 9 of the total number in class 52. After 4 girls are transferred, boys now account for 3 / 5 of the total number

The ratio of boys to girls: (1-5 / 9) / (5 / 9) = 4 / 5
Now the proportion of boys in girls is: (1-3 / 5) / (3 / 5) = 2 / 3
Now the same number of boys as before: 4 / (4 / 5-2 / 3) = 30
Now the number of students in the class is 30 / (3 / 5) = 50

How to find the definite integral of (x ^ 2-1)?

Put the 9 numbers 1-9 into the circle so that the sum of the five numbers in horizontal and vertical rows is 24
The figure is a cross, five circles in horizontal, five circles in vertical, and one number in the middle

The sum of 9 numbers 1-9 is 45, which means that the number shared is 24 × 2-45 = 3
The number of horizontal and vertical lines is 19374 and 28356 respectively

Any two adjacent non-zero natural numbers are coprime numbers______ ．

Any two adjacent non-zero natural numbers are coprime numbers, such as 2 and 3, 3 and 4, 4 and 5, 5 and 6, 6 and 7, 7 and 8, 8 and 9, 9 and 10, and so on

1. Zero is the smallest number in natural number 2. All integers except 0 are natural numbers
Please write down why it is wrong or right

Because natural numbers are non negative integers, that is, positive integers and zeros, positive integers must be greater than zero, so zero is the smallest number in natural numbers;
2 wrong, because integers include positive integers, negative integers and 0, negative integers are not natural numbers, and zero is natural numbers

First row 1; second row 2,3; third row 4,5,6; fourth row 7,8,9,10 Find the sum of all the numbers on line 12

First row 1; second row 2,3; third row 4,5,6; fourth row 7,8,9,10 Find the sum of all the numbers in the 12th line. The first line ending number is: 1. The second line ending number is: 1 + 2 = 2 * (2 + 1) / 2 = 3. The third line ending number is: 1 + 2 + 3 = 3 * (3 + 1) / 2 = 6. The fourth line ending number is: 1 + 2 + 3 + 4 = 4 * (4 + 1) / 2 = 10

The product of three continuous natural numbers can be exactly divided by the sum of 100 natural numbers from 1 to 100. What is the minimum value of the product of three continuous natural numbers

The minimum value of the product is 9999001 + 2 + 3 + +100 = (1 + 100) * 100 / 2 = 5050, and three continuous natural numbers, there must be an even number + two odd numbers, or an odd number + two even numbers. ② there is a number divisible by 3, because 5050 does not contain factor 3, the product is at least 5050 * 3 = 1515015150 = 2 × 3 × 5 ^ 2 × 101

Root 121 equals
I'm very happy. Please answer

11

What should we do next?What's the next s____
She has real r_____ in Henan.Her grandfather was born there

Fill in step
What are we going to do next? What is the next step?
She has real ( easte ) in Henan.Her grandfather was born there
She has real estate in Henan, where her grandfather was born

The plane equation parallel to the x-axis and passing through two points (4,0, - 2) and (5,1,7) is?

(5, 1, 7) - (4, 0, -2) = (1, 1, 9)
(1, 1, 9) x (1, 0 , 0) = (0, 9, -1)
Plane equation 9 (Y - 0) + (- 1) (Z - (- 2)) = 0
9y - z = 2